softfloat: Move minmax_flags to softfloat-parts.c.inc

Rename to parts$N_minmax.  Combine 3 bool arguments to a bitmask.
Introduce ftype_minmax functions as a common optimization point.
Fold bfloat16 expansions into the same macro as the other types.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index 2eb7bb96b3..b9094768db 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -938,3 +938,83 @@ static void partsN(uint_to_float)(FloatPartsN *p, uint64_t a,
         p->frac_hi = a << shift;
     }
 }
+
+/*
+ * Float min/max.
+ */
+static FloatPartsN *partsN(minmax)(FloatPartsN *a, FloatPartsN *b,
+                                   float_status *s, int flags)
+{
+    int ab_mask = float_cmask(a->cls) | float_cmask(b->cls);
+    int a_exp, b_exp, cmp;
+
+    if (unlikely(ab_mask & float_cmask_anynan)) {
+        /*
+         * For minnum/maxnum, if one operand is a QNaN, and the other
+         * operand is numerical, then return numerical argument.
+         */
+        if ((flags & minmax_isnum)
+            && !(ab_mask & float_cmask_snan)
+            && (ab_mask & ~float_cmask_qnan)) {
+            return is_nan(a->cls) ? b : a;
+        }
+        return parts_pick_nan(a, b, s);
+    }
+
+    a_exp = a->exp;
+    b_exp = b->exp;
+
+    if (unlikely(ab_mask != float_cmask_normal)) {
+        switch (a->cls) {
+        case float_class_normal:
+            break;
+        case float_class_inf:
+            a_exp = INT16_MAX;
+            break;
+        case float_class_zero:
+            a_exp = INT16_MIN;
+            break;
+        default:
+            g_assert_not_reached();
+            break;
+        }
+        switch (b->cls) {
+        case float_class_normal:
+            break;
+        case float_class_inf:
+            b_exp = INT16_MAX;
+            break;
+        case float_class_zero:
+            b_exp = INT16_MIN;
+            break;
+        default:
+            g_assert_not_reached();
+            break;
+        }
+    }
+
+    /* Compare magnitudes. */
+    cmp = a_exp - b_exp;
+    if (cmp == 0) {
+        cmp = frac_cmp(a, b);
+    }
+
+    /*
+     * Take the sign into account.
+     * For ismag, only do this if the magnitudes are equal.
+     */
+    if (!(flags & minmax_ismag) || cmp == 0) {
+        if (a->sign != b->sign) {
+            /* For differing signs, the negative operand is less. */
+            cmp = a->sign ? -1 : 1;
+        } else if (a->sign) {
+            /* For two negative operands, invert the magnitude comparison. */
+            cmp = -cmp;
+        }
+    }
+
+    if (flags & minmax_ismin) {
+        cmp = -cmp;
+    }
+    return cmp < 0 ? b : a;
+}